This invention relates to the storage and transportation of goods and, more particularly, to the provision of atmospheres for the storage and transportation of perishable produce such as fruit, vegetables and flowers.
It is known that such perishable produce can be carried in refrigerated containers, sometimes known as "reefers", and refrigeration units for these containers have been developed to provide a reliable piece of apparatus which can usually function for long periods of time without maintenance.
It is also known that during storage and/or transportation the preservation of perishable produce can be enhanced by controlling the atmosphere surrounding the produce. The use in this respect of an atmosphere in which nitrogen (or other inert gas) predominates is particularly useful. Furthermore, in addition to controlling the amount of oxygen present in the atmosphere, there may be a need to control (but not necessarily eliminate) the amount of other substance which may be present, for example carbon dioxide and any ethylene which might be formed by the produce in situ in the container. In addition the level of water vapour in, ie. the humidity of, the atmosphere may be important; commonly, a relatively high humidity is required.
Although a variety of processes and systems have been proposed for the control of such atmospheres, there remains a need for a reliable system which can preferably be sufficiently compact so as to fit within the confines of a standard container or reefer and which can preferably be varied to suit the requirements of the different types of produce being stored and/or transported.